This invention generally relates to a cable or wire cutting device and, more particularly, to a device that is capable of cutting wire sheathing longitudinally and transversely along its circumference more safely and easily than is possible with current devices.
At present, tools are available that are capable of both cutting and stripping an outer sheath of a cable. The most basic tool for cutting and stripping a wire is a conventional utility knife. Such knives have sharp blades and can pose safety concerns.
A modified utility knife such as taught in U.S. Pat. No. 4,081,903 to Cormier may comprise a handle, a removable stripping blade, a cable guide and a cutting blade. The Cormier stripper is similar to a conventional retractable utility knife, but adds a guide that maintains the blade in an engaged position, so that the cable covering can be sliced longitudinally. However, the exposed and protruding blade places the user in danger of being cut.
U.S. Pat. No. 4,026,017 to Arnold discloses another type of stripping tool that uses conventional utility or razor blades. In Arnold, the cable stripping tool has two housing sections with substantially similar shape and size that form a cavity for receiving a conventional razor blade. The housing defines a recess to receive cable in a direction transverse to its length and a has a groove to receive the cable in a longitudinal direction. The cable to be stripped is placed within the recess and the tool is rotated about the cable to cut the sheathing around its circumference without cutting the underlying cable. In like manner, the cable can be pulled through the groove longitudinally so that the blade slices the sheathing in a longitudinal direction. Although the blade is somewhat recessed, the danger of a traditional utility knife is not eliminated because the blade is outwardly exposed within the recess. Furthermore, the tool requires dexterity on the part of the user to maintain engagement between the tool and the cable.
Other stripping tools employ a hinge-type or scissor-type mechanism. For example, U.S. Pat. No. 4,799,406 to Diaz-De-Guerenu-Aguirrebeitia discloses a hinge-type electrical wire stripping apparatus that includes a transverse blade and a longitudinal blade. The apparatus comprises a main body and an arm that can be (a) clamped around a sheathed wire to pierce the wire sheathing and then (b) rotated about the wire to cut the circumference of the sheathing. The apparatus then can be reoriented and reclamped to engage the longitudinal cutting blade and pulled along the length of the wire to cut the sheathing lengthwise and permit the separation of the sheathing from the wire. The clamping and reclamping requires a fair amount of dexterity and effort on the part of the user. Both hands must be used to engage and disengage the tool. Furthermore, the tool must be fully rotated about the wire to complete the circumferential cut. The clamping, reclamping, and full rotation required for this tool all increase the amount of time and effort required to strip the wire.
U.S. Pat. No. 4,117,749 to Economu teaches a hinge-type insulation stripper that has a first pair of jaws with blades extending substantially perpendicular to the axis of the tool, and a second pair of jaws with blades extending substantially parallel to the axis of the tool. First, the first pair of blades is pressed into and rotated about the cable to circumferentially cut the insulation circumferentially. Then, the second pair of blades is pressed into and pulled along the insulation to longitudinally cut the insulation. The tool has many moving parts, including pivoting parts and springs, which makes this tool more complicated and less rugged than non-hinged devices.
U.S. Pat. No. 4,070,930 to Oprins teaches an example of a scissor-type mechanism. The disclosed wire stripper tool comprises a pair of arms joined by a pivot pin. The upper arm comprises a cutting head that supports three blades adapted to slit the insulation around a wire. Two of the cutting blades are arranged parallel to the tool body to make two circumferential slits in the insulation by rotating the tool. The third blade is positioned perpendicular to the tool body to slice through the wire insulation in a longitudinal direction. Thus, the insulation can be peeled away or removed from the underlying wire core. Such scissor-type tools, however, are often bulky, heavy, and difficult to use. For example, the user clutches the tool at a distance from the wire or cable, thus reducing the user's leverage. Additionally, the tool has many moving parts, including pivoting parts and springs.
There have been other attempts to provide a tool that is capable of both cutting and removing the sheath from a portion of a cable. For example, U.S. Pat. No. 4,543,717 to Luka discloses a cable stripper that includes a transverse blade and longitudinal blade that is designed for use with an automated machine. A control mechanism urges continuous contact of the blade and blade holder against the cable surface as the blade holder encircles the cable to score the circumference of the cable jacket. A second blade and blade holder, similarly designed, are pulled in a longitudinal direction to score the cable jacket lengthwise. Thus, the cable jacket can be peeled away and removed. However, this tool is not optimal when stripping only a small amount of wire. Furthermore, the tool suffers from a lack of portability.
Thus, though wire strippers are known, they are typically bulky, difficult to use, complex, and/or unsafe. Industry still seeks a simple, safe, lightweight, and effective tool for stripping wire and cable. It would be an advantage to have a wire stripper tool that self-locks onto the cable to allow essentially one-handed manipulation of the tool. Moreover, it would be desirable to have a handheld tool that that is capable of cutting the cable or wire longitudinally using the blade on one portion of the tool, and cutting the circumference of a cable or wire sheath using a blade on a different portion of the tool, preferably offset from the first portion.
The following disclosure describes a novel tool that overcomes many of the deficiencies of conventional wire and cable stripping tools.